Technically yes, but practically no. If you have the expertise to do it well, or cash to pay for someone else to do it well for you, you can definitely get trus

Technically yes, but practically no. If you have the expertise to do it well, or cash to pay for someone else to do it well for you, you can definitely get trustworthy security boundaries without physical separation. As an example, a VM from a reputable cloud provider is secure enough for most purposes, likewise I'd trust managed containers from a reputable cloud provider (except Azure, they have a dodgy track record when it comes to container security)